If the education secretary didn't exist, how would we invent him? With a compound of arrogance, spite, Thatcherite zeal and incompetence. Days after the government hit teachers with the abolition of their collective bargaining rights, Michael Gove has written to headteachers urging them to dock teachers' pay as punishment for participating in a "work-to-rule" action.

Very much adopting the tone of a school snitch, Gove eggs headteachers on, assuring them that both law and ethics are on their side, and that it will protect "the pupils, parents, teachers and headteachers who would otherwise suffer".

It's worth examining this claim. In September, the NUT and NASUWT agreed to embark on action short of strikes to resist threats to their members' conditions. They said that strikes were held in reserve where management either did not accept the action or attempted to victimise teachers but, as yet, strike action has not taken place. The action involves refusing certain bureaucratic tasks such as lesson observations or mock Ofsted inspections. Instead, they focus on their professional role as teachers. This may be a minor inconvenience for certain headteachers, but the idea that pupils or (heaven forfend) their parents suffer from such action is hardly credible.

Gove's office says that he is responding to an appeal from a headteacher for advice. He may be referring to the head of Stratford Academy, who in October threatened to cut teachers' pay for participating in action short of a strike to oppose attacks on teaching conditions. As the wary response from the National Association of Head Teachers suggests, headteachers are as a rule not interested in such a strategy. Not only that, but they have been sceptical to hostile regarding the government's proposed changes. Thus, Gove's intervention can be seen as an attempt to use the government's authority to back up a belligerent, union-busting minority among headteachers.

The problem for the NUT is that the government evidently thinks the union is weak enough to be baited in this manner. As a rule, the government's worst cuts and anti-union measures have been implemented in a phased manner, ensuring that those who take the hit are either as powerless as possible or as isolated as possible. Since the big strike actions over pensions, which the government didn't expect, they have evidently learned that they have to confront individual groups of workers separately and over a period of time. Now, they have singled out teachers.

Yet why should the NUT be seen as weak? After all, teaching is an essential part of the national infrastructure and every government has a problem attracting enough teachers to fill the necessary roles. The increasing number of people leaving the profession means that any attack on pay and conditions is an attack on the education system. This should leave any government vulnerable.

One reason may be the sense that the union leadership is wary of confrontation. Although the NUT's annual conference supported strike action, the union was not among those participating in the June strikes over pensions. In a ballot earlier this year, teachers also supported a two-phase strategy, beginning with action short of strikes to oppose attacks on pay and pensions, with phase two involving a national teachers' walkout. Phase two didn't materialise.

Such tactical conservatism is not restricted to the NUT executive. It is part of a wider inertia affecting the union leaderships in the UK. It was the same caution that resulted in the unions calling off co-ordinated strike action over pensions after a major mobilisation in November 2011. The last year has been, in the main, one of retreat and losses for the organised labour movement in this country.

There are many reasons why this conservatism persists. The climate is difficult, and unionised workers represent a minority of the workforce. But it's important not to overstate the importance of this. Unions are concentrated in strategically and politically sensitive areas of the economy, which means it is the government that is weakened when strike actions happen. Public sectors workers won the argument with most people during their co-ordinated strike last year.

Second, there have been few major victories chalked up to the labour movement since the Thatcher years. The grip of the "new realism" adopted by union leaders in those days has been difficult to break. But this becomes a self-fulfilling prophecy. If no one fights hard enough to defend their interests, no one will win and the period of malaise will continue.

One final factor is that most of the trade union leaderships are allied closely with the Labour leadership. And many of the measures being implemented by this government were either prepared or anticipated by the last. Undoubtedly, the willingness of union leaders to consider strikes is partly determined by whether they could secure a better deal from Labour. Although the NUT is not affiliated to Labour, the same strategic calculations probably apply.

And that is a serious problem for teachers and for all unionised workers. Get in bed with Labour, and you end up with Gove breathing down your neck.